<!-- 以往 -->
<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Example HTML Page</title>
  <script src="example1.js"></script>
  <script src="example2.js"></script>
</head>
<body>
  <!-- 这里是内容 -->
</body>
</html>

<!-- 现代 -->
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <!-- 这里是内容 -->
  <script src="example1.js"></script>
  <script src="example2.js"></script>
</body>
</html>